I hide the list of all users in Newest Nodes, with Newest Nodes Settings. It's not really worth to display them there imo, as just a new user in itself is not an even I want to check out. If a new user posts a node or talks in the chatterbox, I can notice that directly. If the user writes stuff to his homenode, you're supposed to be able to notice that from Recently Updated Home Nodes, but sadly that node includes all new users, even if they don't touch their homenode. Also, if I really wanted to see a list of recent users, I can always Super Search for them.

Update 2008-06-18: after some nudging, tye has found the problem with the Recently Updated Home Nodes page so now newly created users won't autmatically show up in the list. (Users created before 2008-16-17 are still on the list till they scroll out, we can't fix this retroactively.)